1. Field of Invention
This invention relates generally to compositions for treating impotence, and more particularly to a method for enhancing female sexuality by topically administering a composition whose primary agent is a vasodilator, such as a prostaglandin, and whose secondary agent is a carrier therefor, which composition is applied to the clitoris and the surrounding tissue of the female subject and is absorbed thereby.
2. Status of Prior Art
The term impotence, as applied to sexuality, usually refers to the inability of a male to attain or sustain penile erection. But it is also applicable to aberrations of sexual function in a female, either because of lack of sexual desire or failure to attain orgasm. Hence female frigidity is effectively, female impotence.
In the treatment of male impotence it is known to use prostaglandins for this purpose. One commercially-available form of this substance is identified as Alprostadil, a naturally occurring prostaglandin E-1. This composition is disclosed in "Mechanisms of Action" in Alprostadil Clinical Pharmacology on "Physicians on Line" (http://www.gsm.com). Also of prior art interest is the Scott U.S. Pat. No. 5,708,031 (1998) which discloses the use of prostaglandin E-2 in the treatment of impotence.
Alprostadil is used to treat impotence in adult males and to maintain the potency of the ductus arteriosus in neonates. Two dosage forms are marketed for treating male impotence: an injection form (Caverjet or Edex) that is directly injected into the corpus cavernosa of the penis, and a trans-urethral product, (Muse), which uses a medicated pellet administered into the urethra.
When treating male impotence, Alprostadil relaxes the smooth muscle of the corpus cavernosum. However, the exact mechanism of this action is unknown. The drug may work by increasing the intracellular concentrations of cyclic AMP. Alprostadil interacts with specific membrane bound receptors, thus stimulating adenylate cyclase and elevating intracellular cyclic AMP, leading to the activation of protein kinase with resultant smooth muscle relaxation. Dilation of the cavernosal arteries is accompanied by increased arterial inflow velocity as well as increased venous outflow resistance. Lacunar spaces expand and blood becomes entrapped secondary to compression of the venule against the tunica albuginea. This process is referred to as the corporal veno-occlusive mechanism.
Alprostadil has heretofore been limited to treating male sexual dysfunction. It has not been used to treat female sexual problems, such as frigidity, nor to enhance female sexual response.
Lack of sexual desire or failure to attain organism is encountered much more frequently in women than in men. It occurs in a significant percentage of neurotic women, as well as in other females who exhibit no signs of psychic disorder. (see: Principles of Neurology--Adams and Victor--Third Edition--McGraw Hill Book Company). Yet heretofore effective pharmaceutical preparations for treating women who have difficulty in responding sexually have not been available.
Of general prior art interest is the 1982 U.S. Pat. No. 4,352,790 of Johansson et al. entitled "Medical Preparation Containing Prostaglandin". This patent discloses a preparation intended for intravaginal or intracervical application. The preparation containing prostaglandin is absorbed in a crosslinked hydroxyl group which is insoluble in water but is capable of swelling in liquids containing water to form a gel.
Also of prior art interest is the 1998 patent to Place et al. entitled "Treatment of Erectile Dysfunction." This patent discloses a vasoactive prostaglandin agent administered to the urethra by means of a penile insert to treat male erectile dysfunction.